
precision lowp float;

uniform sampler2D uTexture;
uniform vec3 uColor;

varying vec3 vColor;
void main(){
    // gl_FragColor = vec4(gl_PointCoord,0.0,1.0);

    // 渐变圆
    // float  strength = 1.0 - distance(gl_PointCoord,vec2(0.5)) * 2.0;
    // gl_FragColor = vec4(strength);

    // 实心圆
    // float  strength = 1.0 - distance(gl_PointCoord,vec2(0.5));
    // strength = step(0.5,strength);
    // gl_FragColor = vec4(strength);


     vec4 color = texture2D( uTexture, gl_PointCoord );
    gl_FragColor = vec4(vColor,color.g);
}